package net.sourceforge.jsocks;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.SocketException;
import java.net.UnknownHostException;

/**
 * SocksSocket tryies to look very similar to normal Socket, while allowing
 * connections through the SOCKS4 or 5 proxy. To use this class you will have to
 * identify proxy you need to use, Proxy class allows you to set default proxy,
 * which will be used by all Socks aware sockets. You can also create either
 * Socks4Proxy or Socks5Proxy, and use them by passing to the appropriate
 * constructors.
 * <P>
 * Using Socks package can be as easy as that:
 * 
 * <pre>
 * <tt>
 * 
 *     import Socks.*;
 *     ....
 * 
 *     try{
 *        //Specify SOCKS5 proxy
 *        Proxy.setDefaultProxy("socks-proxy",1080);
 * 
 *        //OR you still use SOCKS4
 *        //Code below uses SOCKS4 proxy
 *        //Proxy.setDefaultProxy("socks-proxy",1080,userName);
 * 
 *        Socket s = SocksSocket("some.host.of.mine",13);
 *        readTimeFromSock(s);
 *     }catch(SocksException sock_ex){
 *        //Usually it will turn in more or less meaningfull message
 *        System.err.println("SocksException:"+sock_ex);
 *     }
 * 
 * </tt>
 * </pre>
 * <P>
 * However if the need exist for more control, like resolving addresses
 * remotely, or using some non-trivial authentication schemes, it can be done.
 */

public class SocksSocket extends Socket {
	// Data members
	protected Proxy proxy;
	protected String localHost, remoteHost;
	protected InetAddress localIP, remoteIP;
	protected int localPort, remotePort;

	private Socket directSock = null;

	/**
	 * Connects to given ip and port using given Proxy server.
	 * 
	 * @param p
	 *            Proxy to use.
	 * @param ip
	 *            Machine to connect to.
	 * @param port
	 *            Port to which to connect.
	 */
	public SocksSocket(InetAddress ip, int port) throws SocksException {
		this.remoteIP = ip;
		this.remotePort = port;
		this.remoteHost = ip.getHostName();
		doDirect();
	}

	protected SocksSocket(InetAddress ip, int port, Proxy proxy) {
		remoteIP = ip;
		remotePort = port;
		this.proxy = proxy;
		this.localIP = proxy.proxySocket.getLocalAddress();
		this.localPort = proxy.proxySocket.getLocalPort();
		remoteHost = remoteIP.getHostName();
	}

	/**
	 * Connects to host port using given proxy server.
	 * 
	 * @param p
	 *            Proxy to use.
	 * @param host
	 *            Machine to connect to.
	 * @param port
	 *            Port to which to connect.
	 * @throws UnknownHostException
	 *             If one of the following happens:
	 *             <ol>
	 * 
	 *             <li>Proxy settings say that address should be resolved
	 *             locally, but this fails.
	 *             <li>Proxy settings say that the host should be contacted
	 *             directly but host name can't be resolved.
	 *             </ol>
	 * @throws SocksException
	 *             If one of the following happens:
	 *             <ul>
	 *             <li>Proxy is is null.
	 *             <li>Proxy settings say that the host should be contacted
	 *             directly but this fails.
	 *             <li>Socks Server can't be contacted.
	 *             <li>Authentication fails.
	 *             <li>Connection is not allowed by the SOCKS proxy.
	 *             <li>SOCKS proxy can't establish the connection.
	 *             <li>Any IO error occured.
	 *             <li>Any protocol error occured.
	 *             </ul>
	 * @throws IOexception
	 *             if anything is wrong with I/O.
	 * @see Socks5Proxy#resolveAddrLocally
	 */
	public SocksSocket(Proxy p, String host, int port) throws SocksException,
			UnknownHostException {
		remoteHost = host;
		remotePort = port;
		remoteIP = InetAddress.getByName(host);
		doDirect();
	}

	/**
	 * Tryies to connect to given host and port using default proxy. If no
	 * default proxy speciefied it throws SocksException with error code
	 * SOCKS_NO_PROXY.
	 * 
	 * @param host
	 *            Machine to connect to.
	 * @param port
	 *            Port to which to connect.
	 * @see SocksSocket#SocksSocket(Proxy,String,int)
	 * @see Socks5Proxy#resolveAddrLocally
	 */
	public SocksSocket(String host, int port) throws SocksException,
			UnknownHostException {
		this(Proxy.defaultProxy, host, port);
	}

	/**
	 * These 2 constructors are used by the SocksServerSocket. This socket
	 * simply overrides remoteHost, remotePort
	 */
	protected SocksSocket(String host, int port, Proxy proxy) {
		this.remotePort = port;
		this.proxy = proxy;
		this.localIP = proxy.proxySocket.getLocalAddress();
		this.localPort = proxy.proxySocket.getLocalPort();
		this.remoteHost = host;
	}

	/**
	 * Same as Socket
	 */
	@Override
	public void close() throws IOException {
		if (proxy != null)
			proxy.endSession();
		proxy = null;
	}

	private void doDirect() throws SocksException {
		try {
			// System.out.println("IP:"+remoteIP+":"+remotePort);
			directSock = new Socket(remoteIP, remotePort);
			proxy.out = directSock.getOutputStream();
			proxy.in = directSock.getInputStream();
			proxy.proxySocket = directSock;
			localIP = directSock.getLocalAddress();
			localPort = directSock.getLocalPort();
		} catch (IOException io_ex) {
			throw new SocksException(Proxy.SOCKS_DIRECT_FAILED,
					"Direct connect failed:" + io_ex);
		}
	}

	/**
	 * Returns remote host name, it is usefull in cases when addresses are
	 * resolved by proxy, and we can't create InetAddress object.
	 * 
	 * @return The name of the host this socket is connected to.
	 */
	public String getHost() {
		return remoteHost;
	}

	/**
	 * Get remote host as InetAddress object, might return null if addresses are
	 * resolved by proxy, and it is not possible to resolve it locally
	 * 
	 * @return Ip address of the host this socket is connected to, or null if
	 *         address was returned by the proxy as DOMAINNAME and can't be
	 *         resolved locally.
	 */
	@Override
	public InetAddress getInetAddress() {
		if (remoteIP == null) {
			try {
				remoteIP = InetAddress.getByName(remoteHost);
			} catch (UnknownHostException e) {
				return null;
			}
		}
		return remoteIP;
	}

	/**
	 * Same as Socket
	 */
	@Override
	public InputStream getInputStream() {
		return proxy.in;
	}

	/**
	 * Get address assigned by proxy to make a remote connection, it might be
	 * different from the host specified for the proxy. Can return null if socks
	 * server returned this address as hostname and it can't be resolved
	 * locally, use getLocalHost() then.
	 * 
	 * @return Address proxy is using to make a connection.
	 */
	@Override
	public InetAddress getLocalAddress() {
		if (localIP == null) {
			try {
				localIP = InetAddress.getByName(localHost);
			} catch (UnknownHostException e) {
				return null;
			}
		}
		return localIP;
	}

	/**
	 * Get name of the host, proxy has assigned to make a remote connection for
	 * this socket. This method is usefull when proxy have returned address as
	 * hostname, and we can't resolve it on this machine.
	 * 
	 * @return The name of the host proxy is using to make a connection.
	 */
	public String getLocalHost() {
		return localHost;
	}

	/**
	 * Get the port assigned by the proxy for the socket, not the port on locall
	 * machine as in Socket.
	 * 
	 * @return Port of the socket used on the proxy server.
	 */
	@Override
	public int getLocalPort() {
		return localPort;
	}

	/**
	 * Same as Socket
	 */
	@Override
	public OutputStream getOutputStream() {
		return proxy.out;
	}

	/**
	 * Same as Socket
	 */
	@Override
	public int getPort() {
		return remotePort;
	}

	/**
	 * Same as socket.
	 */
	public int getSoLinger(int timeout) throws SocketException {
		return proxy.proxySocket.getSoLinger();
	}

	/**
	 * Same as socket.
	 */
	public int getSoTimeout(int timeout) throws SocketException {
		return proxy.proxySocket.getSoTimeout();
	}

	/**
	 * Same as socket.
	 */
	@Override
	public boolean getTcpNoDelay() throws SocketException {
		return proxy.proxySocket.getTcpNoDelay();
	}

	/**
	 * Same as socket.
	 */
	@Override
	public void setSoLinger(boolean on, int val) throws SocketException {
		proxy.proxySocket.setSoLinger(on, val);
	}

	/**
	 * Same as socket.
	 */
	@Override
	public void setSoTimeout(int timeout) throws SocketException {
		proxy.proxySocket.setSoTimeout(timeout);
	}

	/**
	 * Same as socket.
	 */
	@Override
	public void setTcpNoDelay(boolean on) throws SocketException {
		proxy.proxySocket.setTcpNoDelay(on);
	}

	// Private Methods
	// ////////////////

	/**
	 * Get string representation of the socket.
	 */
	@Override
	public String toString() {
		if (directSock != null)
			return "Direct connection:" + directSock;
		return ("Proxy:" + proxy + ";" + "addr:" + remoteHost + ",port:"
				+ remotePort + ",localport:" + localPort);

	}

}
